Our objective is to study antecedents and sequelae of drug use among teenage students and young adults by analyzing a comprehensive, 13-year longitudinal data base collected from 2,500 subjects. Those subjects were in grades 5-10 when our study began in 1969. Between 1969 and 1976, measures were obtained regrading use of illicit drugs, alcohol, and cigarettes; attitudes toward and knowledge about drug use and drug users; attitudes toward cigarette smoking and cigarette smokers; personality; grade point average; school attendance; and school suspensions. Follow-up studies to be performed by mailed questionnaire during 1979-1982 will collect information regarding post high school substance use and significant life events. Topics covered will include current and past use of illicit drugs, alcohol, and cigarettes; education and work experience since high school; social and family adjustment; health and hospitalizations; accidents; attitudes; life satisfactions; personality; interpersonal relations; and deviance.